TL-201 ACCUMULATION IN MYOSITIS-OSSIFICANS AND IN JUXTAARTICULAR OSSIFICATION

We present the findings on Tl-201 and Tc-99m-MDP scintigraphy in three patients suffering from heterotopic ossification (two patients presen ting with myositis ossificans and one patient presenting with juxta-ar ticular ossification in combination with myositis ossificans). Since r esection of the lesions has to be delayed until stabilization, Tc-99m- MDP is Often used as a parameter of lesional activity, although it is not optimal. For this clinical problem, we evaluated Tl-201 scintigrap hy as a marker of metabolic activity. In addition to the well-document ed uptake of Tc-99m-MDP, marked accumulation of Tl-201 was observed in all heterotopic ossification sites. Hence, our results support the us e of Tl-201 scintigraphy in the therapeutic management and monitoring of conditions associated with ectopic ossification. On the other hand, although myositis ossificans is sometimes clinically, radiographicall y and even histologically confused with extraosseous osteogenic sarcom a, Tl-201 accumulation may not be a helpful factor in the differential diagnosis due to the presence of tracer accumulation in both disorder s.